Megawizard FIFO problem: Write and read request filling FIFO!

Strange. A glitch can cause consecutive clock edges faster than the system runs(as well as other issues), causing things to jump to bad states. For example, there are gray-coded counters incrementing, and a glitch could easily cause them to jump to the incorrect state. That being said, it seems like the used words should jump to the wrong value but from there increment/decrement in the correct direction. I don't think there's any sort of state-machine, i.e. anything dependent on the previous state(besides the gray counters themselves). But glad to hear it's working and nice job finding it. That's the type of thing someone like me would spend forever in the part trying to capture/debug.